Currently, people need to use ranging device to measure and plan the route and the area in all aspects of life and work, such as in the field of construction, road engineering, transportation, pipeline laying, landscape areas etc. The most commonly used ranging device is the measuring wheel.
The existing measuring wheel usually only has the function of ranging, its basic principle is to calculate the number of rotation based on the rolling of the measuring wheel and with the help of mechanical gear counter or electronic counter, so as to realize distance measurement. This method usually only measures the length of the traveling trajectory between two points, and then the drawings need to be plotted one segment by one segment. Thus, this method wastes time and the measurement accuracy is very low. Therefore, only limited function may be achieved in actual use.